Teenagers continue to be responsible for a significant portion of all violence in the United States - six in ten youths admitted to state prisons were there for violent offenses, and teens are twice as likely as adults to be admitted for violent offenses (Snyder & Sickmund, 2006). At the same time, exposure to violence is increasingly normative. In 2008 more than 60% of children ages 17 and younger were exposed (directly or indirectly) to violence and more than one quarter had witnessed a violent act in the past year (Finkelhor et al., 2009). The current study integrates two major approaches to the study of violence: longitudinal studies of violence in the life course, and contextual research on violence within disadvantaged neighborhoods. The project has four specific aims: (1) To examine patterns of change in violent behavior in the transition from adolescence to young adulthood; (2) To document levels of stability and change in neighborhood contexts during the transition from adolescence to emerging adulthood; and (3) To investigate associations between stability and change in neighborhood social contexts and individual violent trajectories. To address these aims, the project uses data from the National Longitudinal Study of Adolescent Health and its Wave III Contextual Database (which was compiled by the PI). These data allow us to examine trajectories of change in violence across the first three waves of data collection, as well as changes within the neighborhoods in which respondents were living. We will also examine how changes in violence and neighborhoods are related to residential moves (as opposed to changes in neighborhoods themselves) and to other transitions in family, education, and work during the increasingly diverse and uncertain transition to adulthood. The results of this project will inform prevention and intervention efforts targeting at-risk and violent youth, and will contribute directly to the goals of the Child Development & Behavior Branch (CDBB), as well as those of the Demographic and Behavioral Services Branch (DBSB). By disentangling changes in neighborhoods due to moves from those due to changes in neighborhoods themselves, it may also contribute to a better understanding of the mixed results of the Moving to Opportunity Experiment, as well as research on migration and residential instability. Further, the findings wil speak to recent debates on the relationship between immigration and crime by examining changes in neighborhood racial, ethnic, and immigrant compositions. Finally, the project involves extensive exposure and involvement of both undergraduate and graduate students to the research process.